An affordable automotive hybrid transmission

It is estimated that there are more than 70 automobile models on the road today that use hybrid transmission technology for improving the efficiency of automobile transportation. Most of these transmissions are of the electric hybrid type and are expensive to purchase, and costly to maintain. The original purchase price for a vehicle with an electric hybrid transmission is approximately $8k more than a comparable vehicle without a hybrid transmission and the replacement cost for electric batteries is about$3k every five to ten years with an associated disposal problem for the batteries themselves. This situation has resulted in hybrid vehicle technology being accessible to the few who are able to afford the vehicles and who normally consider themselves to be "energy buffs". By and large, hybrid vehicle technology has not been made accessible to the common automobile owner. This technology is aimed at developing a hybrid vehicle transmission that: 1) reduces the first time buying cost of the vehicle by thousands of dollars, and 2) eliminates the need for replacing expensive and environmentally dangerous batteries thus reducing maintenance costs. It so happens that this technology also eliminates conventional disc brakes that wear out and need replacement. Furthermore, this technology eliminates the reverse gear in the mechanical transmission path thus reducing the cost associated with designing and building this part of the mechanical transmission. This technology will rapidly expand the use of energy-efficient automotives as an affordable hybrid-transmission will be made available for every consumer. With over 60 million vehicles produced every year worldwide this idea will have a tremendous impact on worldwide energy consumption and the environment

Mapping the Efficiency for a Hydrostatic Transmission

Efficiency maps have long been used by engineers to understand the topographical behavior of their machinery. Most commonly, efficiency maps have been generated for internal combustion engines, where the torque-speed curve for the engine shows the wide-open-throttle line with constant efficiency lines drawn beneath this maximum operating limit. From such maps, engineers have been able to determine the most efficiency operating point for the engine, given a desired output power (torque and speed). There currently exists a great interest in using hydrostatic transmissions for improving the operating efficiency of an internal combustion engine. However, efficiency maps for hydrostatic transmissions, similar to efficiency maps for internal combustion engines, do not exist in the literature and therefore it is difficult to assess the overall efficiency gains that are achieved when using a hydrostatic transmission in these applications. This paper proposes a method for generating efficiency maps for hydrostatic transmissions, and presents a typical set of maps that may be used as a first approximation for assessing transmission efficiency. The results of this paper are nondimensional and are generalized for a transmission of any size. As shown in this research, there are regimes of transmission operation in which the efficiency is nearly independent of either the output torque, or the output speed. Furthermore, it is shown that maximum operating efficiencies typically exist at high output speeds, and mid-to-high output torques. [DOI: 10.1115/1.4032289] Introduction Background. A hydrostatic transmission is a continuously variable transmission (CVT) that facilitates power transfer without using a discrete number of gear ratios. These transmissions are frequently used to propel off-highway machinery for the construction and earth moving industry, as well as the lawn and garden industry. CVT technology has also become popular in the on-highway automotive industry as it allows the internal combustion engine of the vehicle to operate at its most efficient operating point for a given power requirement of the vehicle. Some have estimated that a CVT can improve the fuel efficiency of the internal combustion engine by as much as 60

Efficiency Mapping for a Linear Hydraulic-Actuator

This research is aimed at generating an efficiency map for a linear hydraulic-actuator that is controlled using an open-centered 4-way valve. Using the basic configuration of a double rod, doubleacting linear actuator, equations for describing the input and output power of the actuator are written and nondimensionalized to produce a nondimensional map for the efficiency of the actuator itself. In conclusion, the actuator is shown to operate below a wide open valve (WOV) line with efficiencies that are typically less than 50%. Note that the WOV line describes the maximum actuator-force that may be achieved at a given actuator-velocity. While the actuator chosen for this paper is common, extensions of the methods used in this study may be applied to double-acting, single-rod designs or single-acting, single-rod designs. Furthermore, it is anticipated that this type of analysis may also be used to study the effects of power regenerating valves and for predicting the efficiency improvements that may be gained for linear hydraulic-actuators that use this type of valve design

Select Scenes from Noah D. Manring's Industrial Seminar for Engineers

Date of publication unknownDate of publication unknownThis video presents clips from Noah Manring's industrial seminar for engineers on hydraulic control systems

Torque on the cylinder block of an axial-piston swash-plate type hydrostatic pump

In this dissertation, both the ideal and non-ideal torque on the cylinder block of an axial-piston swash-plate type hydrostatic pump are examined. Traditionally, the torque on the cylinder block has been estimated by using a standard theoretical-expression that does not consider the compressibility of the fluid or the frictional characteristics within the pump. Furthermore, past research that has considered fluid compressibility and friction has been conducted on a macroscopic level and simply emphasizes test results without offering sufficient explanations for them. As the need for improved efficiency of hydrostatic pumps increases, an improved understanding of the torque characteristics within these machines is required;This research compares the results of a detailed mathematical-model with actual test-data for the torque on the cylinder block of an axial-piston swash-plate type hydrostatic pump. As a result of this analysis, an improved model for the idealized torque on the cylinder block is offered in closed-form. Furthermore, a numerical program is written to calculate the net torque on the cylinder block which includes the torque that is lost due to friction. Using the numerical model, the torque losses are separated for each component within the machine and compared with each other to determine where the torque losses are greatest. Lastly, basic design parameters are numerically varied by small amounts to determine the magnitude of influence that specific design changes might have and it is shown that some design changes have greater influence on the torque loss than others.</p